This invention relates to a metallic scale and a method of manufacturing the same. Such metallic scales are used to measure stroke or displacement of a component element of an automatic machine which operates at a high speed or at a variable speed such as an injection molding machine or a die casting machine. Measuring instruments utilized in such application generally have a short operating life and their characteristics are not always satisfactory. Especially, where the acceleration of the movable element increases to about 20 G, conventional measuring instruments are not yet satisfactory from the standpoints of their life, response speed and cost.
In a die casting machine, high speed metal molding machine or the like, for the purpose of manufacturing products having an excellent quality at a high yield it is essential to strictly control the speed, acceleration and displacement or stroke of a ram connected to the piston rod of a fluid actuator. However, at present it is difficult to avail a measuring instrument when the maximum acceleration of the ram reaches 50 G.